Yale 2014 - 1 - Iron Deficient Anemia

Question 1

What is the prevalence of Iron Deficient Anemia in Age >65?

Answer 1

15%

Question 2

How do you distinguish IDA from other causes- First lab test to order ?

Answer 2

Serum Ferritin
100 excludes IDA
Issues- Many inflammatory states can elevate Serum Ferritin but >100 still excludes IDA

Question 3

What is the biologic role of Ferritin and Transferritin?

Answer 3

Ferritin - primary iron storage protein in the body. It is an excellent indicator of iron stores in healthy adults.
Transferritin - Protein used to transport iron in the circulation.

Question 4

What is TIBC?

Answer 4

A medical laboratory test that is used to indirectly measure the bloods capacity to bind iron with transferrin. It is increased in IDA.

Question 5

What is soluble transferrin receptor test?

Answer 5

Serum component of the iron binding receptor on the cell membrane. Elevated in IDA.

Question 6

What is the Erythrocyte Protoporphyrin receptor?

Answer 6

The precursor to heme before iron is bound. Increased in IDA. If you have already ordered the standard work up for IDA and still are not sure, ordered this test.

Question 7

What are the major categories of IDA etiologies?

Answer 7

Poor Absorption of iron
Iron Loss
Inadequate iron intake

Question 8

Most common cause of iron deficiency?

Answer 8

Blood loss usually from menstruation or via GI tract due to NSAID use or cancer or abnormalities of the gut including angiodysplasia, celiac disease, peptic ulcer disease, esophagitis, or vascular ectasia.

Question 9

What is the first step for post menopausal women or men with IDA? Next step?

Answer 9

Exclude GI losses (upper and lower endoscopy).
Next step includes r/o absorption issues by ordering a Tissue Transglutaminase test and if positive needs a duodenal biopsy.

Question 10

How do you replace iron in IDA? Expected Response?

Answer 10

Goal is to give about 5000mg of elemental iron over 3-6 months. About 10% of which is absorbed (500mg).
Goal is to use IronSulfate 365mg up to TID as tolerated (Gi Issues common)
Adequate response would for 500mg elemental iron absorbed would see an increase of about 2g Hgb or (500ml of RBC)
If intolerant can also try using iron gluconate or iron fumerate which have 30mg of elemental iron.